Pneumatic thread holder for weft replenishing looms



Feb. 17, 1953 J. T. KENNEDY 2,628,640

PNEUMATIC THREAD HOLDER FOR WEFT REPLENISHING LOOMS Filed May 31, 1951 llllllllill 6 INVENTOR 26 5% JOHN T. KENNEDY H 41 55 3O 35 5Q H aw z 47 ATTORNEY.

Patented Feb. 17, 1953 PNEUMATIC THREAD HOLDERFOR. WEFT REPLENISHING Looms.-

John T. Kennedy, Worcester, Mass., assignorto -Orompton & Knowles Loom Works, Worcester,

Mass., a. corporation of Massachusetts 7 Application May 31, 1951, Serial No. 229,015

This invention relates to improvements in pneumatic thread holders and removers for weft replenishing looms and it is the general object of the invention to. provide a thread holder of this type so constructed as to permit the use of a large intake mouth for the weft ends of reserve bobbins without requiring an excessively large air pump. f v

It has been proposed heretofore to provide a weft replenishing loom with a pneumatic thread holder provided with an intake mouth into which the weft ends of reserve bobbins extend. holders of this typeoperatewith a pump which acts to create subatmo'spheric pressureswithin the system so that the intake mouth acts in the capacity of a leak in a partial vacuum systemj Pneumatic thread holders made inthis manner are necessarily made with small intake mouths in order to reduce the leakage and the work required to produce subatmospheric pressures, but small mouths cannot satisfactorily handle a large number of weft ends, particularly if weft ends are coarse or are hairy yarns.

It is an important object of the present invention to provide a pneumatic thread holder in which an injector introduces compressed air into a thread holder tube or the like one .end of which is open for ingress of air the otherend of which is open for the egress of air, and wherein a relatively large intake mouth for the weft ends is located between the open ends of the tube. A relatively large intake mouth will have a sufficient perimeter to accommodate more weft ends than is possible with small mouths such as are now in use.

A disadvantage which sometimes attends the use of a pneumatic thread holder is that turbulence in the thread holder tends to twist the threads on each other so that an individual thread is not readily detachable from a group of threads when it should be free to be drawn into the thread holder and disposedof. It is another object of the present invention to provide a form of thread holder employing an injector tube the position of which can be adjusted with respect to the weft end or thread intake mouth for the purpose of reducing to a minimum the twisting of the threads on each other.

In the usual form of pneumatic thread holder all of the air which comes into play in subjecting the Weft ends to pneumatic traction must} g It is a still further object of the present invention to probe supplied by a pump or the like.

In most instances pneumati thread 9 Claims. (01. 139-247) vide a. formof thread holder in which an injector tube is extended into an open end'of a'thread holder tube of considerably larger diameter and locate the nozzle of the injector tube between the ingress end of the thread tube and the thread intake mouth so that air issuing from the nozzle can draw air in through the ingress end of the thread tube to increase the total volume of air moving through the holder and acting on the weft ends." I

Whenja column of air is moving through a tube or the like the air near the cross-sectional center ofthe tube moves much more rapidly than does the air adjacent to the inner walls of the tube. When'the thread intake mouth is in the form of an aperture cut into a tube the Weft ends tend to cling .to the walls of the tube where the air is moving slowly and underthese conditions the threads are not subjected to the maximum pneumatic pressuresavailable. It is a further object of the ,invention to locate the aforesaid injector tubexnear; the axis of the thread tube so that a hollow column of air will be drawn into the ingress end of the thread tube and travel along the inner walls, of the tube, thereby 'increasing'the rate of flow of air at those parts of the tube where the weft ends are located.

In orderthat theinvention may be clearlyv 'understood'reference. is'made to the accom panying drawings which illustrate by way of example two embodiments of the invention and in which: I

Fig. .1 is a side elevation of part of a loom having the preferred form of the invention applied thereto, I

Fig. 2 is an enlarged plan'view looking in the direction of arrow 2, Fig. 1,

Figs. 3, 4, 5 and 6 are enlarged vertical sections on lines 3--3, 4'4; 55 and 6-8; re.-

spectively, Fig; 2.

Fig. 7 is a perspective view of the thread holder intake tube forming part of the present invention,

Figs. 8 and 9 are diagrammatic'views showing the'manner of adjusting the injector tube with respect to'the thread holder tube, and

Fig. 10- is a view'similar to Fig. 9 but showin a modified form for the invention wherein flared or bell shaped ends are. provided for the ends of the thread holder tube.:

'Referring particularly to Fig. 1, the loom L is.

These stacks of bobbins await transfer by the usual bobbin changing mechanism and all of the bobbins have their weft ends extended toward a thread holder which is indicated generally at H. As shown more particularly in Fig. 2 the weft ends are arranged in four groups, the ends WI and W4 being for the front and back stacks l and 4. respectively, and the groups W2 and W3 corresponding respectively to the stacks 2 and 3. At the time of bobbin transfer the selected bobbin is pushed down into one of several shuttles one of which is shown at S on the lay 5 in Fig. 1. The weft end of the transferred bobbin must be held tightly enough to effect self-threading of the shuttle, and at some subsequent time this end is cut at the selvage of the cloth and should be removed to prevent it from being whipped into the shed to produce a blemish in the cloth.

The loom may be driven in usual manner and K has top and bottom shafts l and II, respective.- ly, anda topv gear i2 on shaft [0 meshes with and drives a gear l3 of twice its size on shaft II. A driving motor [4 has a pinion l5 meshing with a gear It for driving the top shaft [0. The motor and gear [6 will ordinarily be running during any period of weaving even though the loom should be temporarily stopped by one or another of the stop motions with which it is equipped. Shipping and braking mechanisms will be of usual form but are omitted from the drawings and may be controlled by handles one of which is shown at H, Fig. l.

The matter thus far described is of common construction and operates in the usual manner and of itself forms no part of the present invention.

In carrying the invention into effect I provide a source of compressed air, shown herein as an air pump P supported on the loom by a stand and driven by the motor gear [5. Leading forwardly from the pump P is a hose or pipe 2| which in the present instance carries compressed air derived from the pump as distinguished from those forms of pneumatic thread holders wherein the pump creates a partial vacuum. The pump as shown will run continuously while gear [6 is turning, but the pump need not necessarily be operated as set forth herein, since it will be sufficient for the purposes of the invention if air under pressure can be created within the pipe 2| for the purposes of the invention.

The magazine has secured thereto an arm '25 the lower end of which is secured by bolts 26 to a support 21 extending back and forth in the loom and spaced outwardly from the tip ends of the bobbins in the magazine M. This sup-port has a base 28 provided with an upright bearing 29, for a thread holder elongated tubular member 30. The base 28 is also provided with an upright head 3| which is splitas at 32 so that it can be clamped against the tube by a clamp screw 33, as shown in Figs. .4 and 5. The tube 30 extends forwardly, to the left as viewed in Fig. 2, from the bearing 29. but may if desired terminate close to the head 3|, as shown in Fig. 2. The tube is open at both ends and at a convenient point intermediate its ends is provided with a thread intake mouth designated at 35.

Provision is made for separating the groups WIW4 of weft ends from each other as they enter the mouth 35, but this thread separatin feature is not essential to the invention. A depending arm 36 on the base 28 is provided with two screws 37 and 33 having clamp nuts 33 between which are held the feet of separator plates or vanes which in the present instance are three in number. The front vane 40 has the upper part thereof inclined forwardly while the rear vane 4| has its upper part inclined in the opposite direction, and the third vane 42 is flat and intermediate vanes 40 and 4| and spaced from them. The groups W2 and W3 lie on opposite sides of the intermediate plate or vane 42 and are guided by their vanes 40 and 4| respectively toward the mouth 35. The front and back groups WI and W4 enter directly into the thread mouth 35 without being guided by the vanes.

Extending horizontally and rearwardly from the base 28 is an arm 45 having an upright mounting means 48 at the rear end thereof for an injector tube 41 preferably concentric with tube 30 and held in position by a set screw 43. The set screw permits the injector tube to be adjusted back and forth in a direction lengthwise of the thread holder tube 30, and also angularly around its axis.

The injector tube extends into the rear ingress open end 50 of tube 30 and is disposed more or less concentrically with tube 30, as shown in Fig. The end of tube 41 in tube 30 may be reduced to form an elongated forwardly opening outlet or nozzle 5i the angular position of which may be adjusted relatively to mouth 35. The rear end of the injector tube 4'! is connected as at 52 pneumatically to the forward end of the previously described pipe 2 I. As will be apparent from Fig. 5 the diameter or internal cross sectional area of the thread holder tube 30 is considerably larger than that of the injector tube 41 so that there is considerable space inside the tube 30 around the tube 41 and this space is open to the atmosphere.

During operation of the loom the .pump P will cause a blast of air to issue forwardly from nozzle 5! within the tube 30 and in doing so will draw air into the ingress opening 50 of the tube 30 to increase the volume of air moving through the thread holder tube 30 beyond that derived from the injector tube. As this air rushes past the mouth 35 air from the surrounding atmosphere is drawn into the mouth and carried along forwardly in the tube 30 to the outlet or egress end 55 of tube 33. By adjusting both the longitudinal and angular position of tube 41 the nozzle can be located at the optimum position for the particular type of weft on the bobbins to reduce to a minimum turbulence within tube 30 tending to 3 cause the threads to twist together. The

nozzle is located intermediate the intake mouth 35 and the open rear end 50 of the thread holder tube 30, and depending upon the position of the nozzle the thread holder will be adaptable to yarns of different kinds.

Figs. 8 and 9 show two positions for the tube' 41 with respect to the thread mouth 35. In both of these positions the nozzle is spaced sufficiently rearward of mouth 35 to prevent blowback or escape of air out of the mouth 35. The

column or blast of air moving to the left as viewed in Fig. 2 will direct the weft ends, designated collectively at W, forwardly toward some form of entangling means which will hold them.

This device is shown herein as an open coil spring extending into the blast of air and having its upper end secured at 5| to a part of the magazine M. The weft ends W will become sufliciently entangled with the spring so that at the time of picking of the freshly replenished shuttle the corresponding weft end aeeae i'o will be held to effect self-threading f the shuttle. The column of air moving through the tube will resist retrograde motion of the thread of the replenished shuttle, but it is found more advantageous to rely upon mechanical entanglement of the weft end to prevent retrograde motion rather than to depend upon pneumatic pressures-solely for this purpose.

It will be observed from Fig. 2 that the intake mouth is relatively large and has a suihcient capacity to accommodate a number of coarse threads which can be distributed around the upper inner part of the tube 3% and therefore be separated from each other to a larger extent than is possible where a small intake mouth is used.

From Figs. 5 and 8 for instance it will be understood that because of the injector tube the column of air entering the open end will be tubular in cross section and will be caused by injector tube 41 to move along the inner wall of tube 39 to exert pneumatic traction on the weft ends entering mouth 35 to a greater extent than would be the case if the injector tube 41 were not extended into the tube 39.

In actual practice it has been found that satisfactory results can be obtained if the distance from the mouth 35 forwardly to the open end is about 8 times the diameter of tube 30 and if the intake mouth has a width equal to three-quarters of a diameter of tube 36, and if the distance between the mouth 35 and the rear open end 50 is about twice the diameter of tube 30. Also, it is found that if the injector tube 41 has a cross-sectional area of about one-eighth that of tube 30 satisfactory results can be obtained without utilizing air under excessively high pressures.

The intake mouth 35 is disposed more or less as indicated in Fig. 4, that is, it opens toward the magazine although there is a part of it which opens upwardly. Because of the added amount of air introduced into the tube 30 through its open end 50 the diameter of tube 39 and the mouth can be made quite large so that, as will be apparent from Fig. 4, a large perimeter of the mouth is available for distribution of the weft threads.

In the modified form of the invention provision is made for still further reducing air 0 turbulence within tube 36. The forward end of tube 30 is fitted with a diverging end or bell 55, while the rear end of tube 39 has a bell shaped fitting 6%. These bells may be fitted snugly over the ends of tube 35 and held in position frictionally by their cylindrical parts 67, or may be permanently connected to the tube 30.

From the foregoing, it will be seen that the invention sets forth a simple form of pneumatic thread holder comprising an outer thread holder tubular member 30 open at both ends and an inner injector tube for compressed air the nozzle end of which is located between the ingress end of the outer tube and the thread intake mouth 35. It will also be seen that the injector tube has the effect of introducing a hollow cylinder of air into end 50 which tends to move along the inner walls of the tube 3%) and create increased pneumatic traction on the weft threads. Also, the injector tube is adjustable lengthwise and angularly of the tube 39 to accommodate the holder to use with weft ends of varying sizes. It is found that by proper location of the nozzle turbulence and resulting twisting of the weft ends can be reduced so that the weft ends lie more or less straight without becoming entangled with each other within the tube 30 and are thus free to be drawn into the mouth 35 and blown toward spring (it when out from the selvage. The bells and 66 can be used when desired to still further reduce air turbulence in tube 39.

Having now particularly described and ascertained the nature of the invention and in what manner the same is to be performed, what is claimed is:

1. In a pneumatic thread holder for the wef ends of a weft replenishing loom provided with a source of compressed air, an elongated tubular member open at each end thereof and having a thread intake mouth for the weft ends intermediate the ends thereof, and an injector tube pneumatically connected to said source extending into one end of said tubular member spaced from the latter and having an air outlet nozzle opening toward the other end of the tubular member located intermediate said intake mouth and said one end of the tubular member effective when discharging air from said source into said tubular member to draw air from the atmosphere surrounding said one end of the tubular member into the latter to increase the flow of air within the tubular member past said intake mouth beyond that derived from the injector tube.

2. The thread holder set forth in claim 1 wherein the injector tube is substantially concentric Wi-th the tubular member and is effective to draw a tubular column of air into said one end of the tubular member.

3. The thread holder set forth in claim 1 wherein said nozzle is elongated and provision is made for angular adjustment of the injector tube to vary the angular position of the nozzle with respect to the thread intake mouth.

4. The thread holder set forth in claim 1 wherein provision is made for adjusting the injector tube lengthwise of the tubular member to vary the distance between the thread intake mouth and said nozzle.

5. The thread holder set forth in claim 1 wherein the nozzle is of elongated cross section and provision is made for adjustment of the injector tube angularly to Vary the angular relation between the elongated nozzle and the intake mouth and also lengthwise of the tubular member to vary the distance between said elongated nozzle and the thread intake mouth.

6. The thread holder set forth in claim 1 wherein the length of that part of the tubular member extending beyond the thread intake mouth in the direction of flow of air in the tubular member is substantially eight times the internal diameter of the tubular member.

7. The thread holder set forth in claim 6 wherein the length of that part of the tubular member extending between said thread intake mouth and said one end of the tubular member is equal substantially to twice the internal diameter of the tubular member.

8. The thread holder set forth in claim 1 wherein said one end of the tubular member is provided with a bell-shaped fitting through which air from the surrounding atmosphere enters said one end of the tubular member.

9. A thread holder unit for the weft ends of a weft replenishing loom, said unit comprising a support, a thread holding tubular member open at both ends thereof and having a thread intake mouth therein between the ends thereof, means on the support to secure the tubular member to said support with said, mouth spaced from the means longitudinally of the tubular member, an injector tube of less cross sectional area than the cross sectional area of the inside of the tubular member having an air delivery nozzle at one end thereof, mounting means on said support holding the injector tube with said one end thereof projecting into one end of the tubular member and with said nozzle located between the thread 10 Number intake mouth and said one end of the tubular member, and adjusting means on the mounting means to change the position of the injector tube longitudinally of the tubular member to vary the 8 distance between the thread intake mouth and said nozzle.

JOHN T. KENNEDY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date 1,703,898 Payne Mar. 5, 1929 1,722,930 Lundgren July 30, 1929 2,358,952 Turner Sept. 26, 1944 

